PCT Publication WO 2003/062198 describes integrin targeted nanoparticles as imaging agents and drug carriers wherein the targeting moiety is coupled to the particle through anchoring a linker coupled to a peptidomimetic into a lipid/surfactant layer coating the particles. Exemplified as such a linker is a long chain polyamide containing two chiral centers and including a segment of polyethylene glycol (PEG). The linker is coupled to phosphatidyl ethanolamine (PE) through an amide linkage to the nitrogen of the ethanolamine.
The present invention is directed to improved linkers which couple targeting agents to lipid/surfactant anchoring moieties.